Tire-deflation indicator



`Iune 17, 1930. R. DEPEE 1,765,213

TIRE DEFLATION INDICATOR' Filed Feb. 8, 1927 Strom,

-mvm

A further object is to provide a device l adapted to he threaded on theupper end in ressure in the tire.

a tire valve stem to replace the usual valve cap and adapted to actuatea suitable switch lwhen the tire becomes deiated to give the operator ofthe vehicle an indicatin signal. A further object is to provide a aeviceol the character just mentioned wherein loclzing means for the switchactuating device is provided and adapted to be maintained in lockedposition when the tire is properly inated, and adapted to be unlockedupon deation of the., tire below a predetermined pressure whereby theswitch will be actuated to rovide a signal.

further obJect is to provide an expansi hle member adapted to hold theswitch actuating device in unlocked position when the'tire is properlinflated, and to provide resilient means a apted to contract theeirpansible device upon a predetei mined drop further object is toprovide a switch device carried by a stationar part ofthe vehicle suchas the trame, en an actuating device for the switch carried by a wheelol the vehicle and normally arranged in such a position that the switchis out of the path ci travel thereo, the switch actuating inem- -herhaving aportion movable laterally with ligure 1 is a sectional viewthrough a vehicle wheel and associated elements showing .applicationtiled the device in elevation,

2 is a central sectional view through the device,

Figure 3 is a section online 3--3 or .lligg position, parts being shownure Figure l is a detail pers tive ci: the lool-ring device for theswitch actuating means, and associated elements, and,

Figure 5 is a diagrammatic view showing the e ectrical connections ofthe device.

Referring to the drawings the numeral 10 designates an axle or a vehicleupon which is mounted a wheel 11 having a pneumatic tire 12 mountedthereon and provided with the usual valve stem 13. The valve stem isprovided with the usual valve having an ,v ward projection 14 which isadaptedv to fr. depressed to open the valvein the usual manner. A frame15 is 4suspended above the axles of the vehicle by the usual springs 16,and a mud ard 17 covers the lwheel 11 as shown in Figure 1.

'lhe device formin the subject matter of the present applicationincludes a thimble 18 which is threaded on the upper end of the valvestem 13, replacing the valve ca usually employed. The thimble is provied with a head 19 having a downwardly projecting lug 20 which engagesthe projection ld to hold the tire valve in open position when thedevice is applied in the manner shown. The head 1.9 is urtherprovidedwith a small passage 21 through which air is adapted to pass when thevalve is held in open position in the manner indicated.

.il sleeve 22 is internally threaded. at its lower end to receive theexternal threads of the upper end of the thimble 18. 'lhe upper end ofthe sleeve 22 is provided with an axial opening 23 in which a stem 24 isslidably mounted. A. head 25 is mounted to reciprocate 'within thesleeve 22 and is connected to or formed integral with the stem 24. rl`hesleeve 22 is provided with a coil spring 26 arranged therein, and theupper coils of this spring engage a thread groove 27 formed in thesurface of the head 25 whereby this element will be secured to thespring. ln a similar manner, .the lower "lll apparent that when thesleeve 22 is securedin position, the shoulder serves to securel clampthe -flanges 29 and 33 against the thimble 18, thus preventing theleakage of air from the interior of the member 31. The expansible member31 is preferably formed of rubber, and it will be apparentv that theintroduction of `air thereinto is A ada ted to cause this member tobecome exten ed vertically, the spring 26 acting as confining means toprevent transverse expansion. Since the projection 14 is depressed whenthe device is in operation, it will be a parent that air under pressurewill be supplled to the interior of the expansible member 31.

A cap 34 is threaded on the upper end of the sleeve 22 as clearly shownin Figure 2. The cap 34 is provided with a cylindrical bore in which alock actuating member 35 is mounted to reciprocate. The upper face ofthe member 35 is substantially conical, as indicated at 36, while thismember is provided in its lower face with a recess or` depression 37 inwhich the stem 24 projects.-

he cap 34 i's provided with a head 38 having an axial opening thereinthrough which a stem 39 projects. This stem is provided pivotal dicatedat 49. One end of the bell crank at its lower end, within the ca 34,with a cross head 40 to opposite en s of which locking members 41 arepivoted. Each locking member is provided with an outwardly projectingfinger adapted to engage in an annular groove 43 formed withln the cap34 for a purpose to be described.

A spring'44 is rovided for normall moving the stem 39 inwardly radiallywith respect to the vehicle wheel, one end of the spring being connectedto the stem 39. A bracket 45 is preferably formed integral with thecapw34` and is provided with an overhanging end 46 to which the otherend of the s ring 44 is attached. The stem 39 is provi `ed with a fingerpiece 47 by means of which 'the stem 39 ma be set in normal runningposition. A bel crank lever'48 is y connected to the bracket 45 asinlever is provided with a slot 50 to receive a pin 51 carriedby the uper end of the stem 39. The other end 52 o? the bell crank lever isadapted to be swung outwardly upon upward movement of the stem 39 tooperate a switch to be described.

Referring to Figures land 3, the numeral portion of the vehicle.

'ed to secure the clamp in be controlledl by scribed through the mediumof electric cir- 53 designates a supporting bracket carried by theframeor other relatively stationary The bracket 52 v1s preferably tubular andis provided with a flan e 54 adapted to en age the outer face of tevehicle frame, an a nut 55 is adaptition, as shown in Figure 3. A,switch in icated as a whole by the numeral 56 is arranged on the outerend ofthe bracket 53'. This switch includes a stationary member' 57having a swinging arm 58 pivotally connected at one yend thereto. A coilspring 59 is connected at one end to the stationary member 57 and at itsopposite end to the switch arm 54 and normally holds the latter in theVsolid line position shown in Fi re 3. A stop 60 carried by the member 5ment of the arm 58 yond normal position.

A stationary switch` arm 61 is carried b :the

outer end of the bracket and is insu ated therefrom as indicated at 62.The stationary switch arm is provided at its outer end with a contact 63adapted to be engaged by the switch arm 58 when the latter 1s swung tothe dotted line position, in a manner to be described.

While I have described one of the devices adapted for connection to avehicle tire, it will be apparent that each tire of the vehicle isprovided with such a device, and means are arranged adjacent the driversseat to give suitable indication to the driver of the vehicle when oneof the tires becomes defiated. Such indicatin means is adapted to theevice previously (lecuits illustrated in Figure 5. Referring to 'thisfigure, the numeral 64 vdesignates a source of current having oneterminal grounded tothe frame of the vehicle as indicated at 65. Theopposite terminal of the battery-is provided with a lead wire 66, andthis wire 1s connected by branch wires 67 with a plurality of li hts orother signals 68. These si nals pre erably are arranged on the dash othe vehicle in such a manner as to correspond as to the number andarrangement of the vehicle tires, and the opposite terminal of each sial is connected to one of the switches 56. rom each switch 56 thecurrent passes to a ground .69, when thc switch is closed, and hencereturns to the source of current throu h the ground 65.

The operation of the evice is as follows: A tire is infiated in theusual manner, whereupon the .device is placed in position by threadingthe thimble 18 on the valve stem. This action causes the tire valve tobe'opened,thus permitting the escape of air under pressure 1nto theexpansible member 31. The sprin 36 obviously confines the expansible memr, and accordin 1y the latter becomes extended longitudinaly and itsclosed end moves the stem 24 inwardly rap'events turning moveiusl diallywith respect to the wheel. The spring 26 is of the retractile type, andthus opposes the expansive movement of the member 31. The degree lofpressure necessary to operate the device obviously depends After thedevice is in position, the memberv 35 will support the arms 41 with thelingers thereof above the annular groove 43. The stem 39 is thendepressed by pushing upon the finger piece 46, and as soon as thelingers 42 coincide in position with the groove 43, the conical head 36moves the arms 41 outwardly whereby the fingers 42 engage within thegroove 43. The upward pressure ex- -erted on the member 35 causes thearms 41 to retain the`position just referred to, thus preventing upwardmovement of the stem 39. The bell crank lever will then be arranged inthe position shown in Figures 1 and 2, and the vehicle is driven in theusual manner. With the parts in the position shown, the movable switcharm 58 is arranged out of the path ofvtravel of the end 52 of the bellcrank lever 48, and accordingly the switch arm is in the solid linepositlon shown in lFigure 3. If the tire be.-

comes deflated beyond a predetermined pressure, the spring 26 acts toovercome the expansive action of the air upon the member 31, thusretracting the head and stem 24. Thev member thereby releases the arms41, and the sprin 44 moves the stem 39 inwardl radially with respect tothe vehicle whee This action obviously swings the bell crank lever aboutits pivot 49, and moves the end 52 of the bell crank lever inwardly.Under such conditions, the movable switch arm 58will be arranged in thepath of travel of the end of the bell crank lever, and upon continuedrotation of the wheel, the switch arm 58 will be swung tov the dottedline position shown in Figure 3.

It will be apparent that the spring 59 passes` the center of the pivotof the arm 58 as the latter is swung to either extreme position, and thespring 59 therefore serves to hold the switch arm in either position.When the switch arm is swung to the dotted line position shown in Figure3, it will close a circuit to the correspondin signal whereby theoperator of the ve icle will be provlded with a' signal indicating thatthe corresponding tire has become deflated. The switch arm 58 is resetbefore proceeding to drive the vehicle, and after the deflated tire hasbeen inflated or repaired.

It is to be understood that the form of the invention herewith shown anddescribed is to be taken as a preferred example ofthe same and thatvarious changes in thel shape,

size and arrangement of parts may be re.- sorted to without departingfrom the spirit of the invention or the scope of the subjoined claim.

I claim:

A- device of the character described com,- prising a thimble threaded atits lower end for connection with the valve stem of a pneumatic tire andprovided with a head adapted to hold the valve thereof in open position,a sleeve arranged in axial alinement with said thimble and threaded.thereto, said head being provided with lan opening, a longitudinallyexpansible member arranged in said sleeve and having a flange at itslower end clamped between said thimble and said sleeve, a stem slidablein the upper end of said sleeve and projecting upwardly therebeyond, ahead arranged on the lower end of said stem .and contacting with theupper end of said expansible member, a cap arranged on the upper end ofsaid sleeve, a slidable member arranged in said cap and contacting withthe upper end of said stem, signal actuating means including a stemsl1dable in thefupper end of said cap, said slidable member beingadapted to lock said last named stem against movement when the pressurein said expansible member is above a predetermined point, said slidablemember being movable downwardly upon a decrease in pressure below suchpredetermined point to release said last named stem, said cap be-` ingprovided with lany internal annular groove, arms carried by said lastnamed stem and having fingers at the lower end thereof e ageable in saidgroove, the upper face of said slidable lnember being conical andadapted to lengage said arms to urge the lingers thereof outwardly intoengagement with said groove, and resilient means normall urging saidlast named stem upwar y.

In testimony whereof I affix my signature.

ROY DEPEE.

